COMMUNITY FORUM

Pipe Sizing Question / Copper/PEX

I have a 5BR/3bath home in NNJ, orig. built in the '30's but now had many additions and upto date services, but, still much speghetti plumbing in the basement from all the additions. I think they are all fine by code, but, its pretty tough to follow in the basement - pipes to "nowhere" etc. I am installing a Water Softener (WS), and will take the opportunity to clean up old plumbing where I can. It's all copper, but, was thinking of making a cold water manifold post-WS, and create as many home runs as I can with 1/2 PEX, and get rid of the spaghetti. The a 1" copper main that splits-- 1" to outside sillcocks, and 3/4" to service the WS/inside. I was thinking of keeping that 1" to the WS and making the manifold 1", where I would then have the 1/2" PEX "home runs" and 3/4 to feed the HWH and other distribution pipes.. My goal is to clean things up, which this will, but, and hopefully maximize volume at the sinks -- but, am I missing anything, or should I just keep it all 3/4" after first split from the main. Thanks

2. The thing to remember about home run plumbing is at every faucet that runs back to that manifold you are going to be waiting for hot water (or cold for that matter) as opposed to a main pipe running through and each fixture tapping off of it.

I would also consider running a full 1" main and branch off to 3/4 copper to each bathroom

The problem with undersizing the supply lines especially in older homes is loss of volume. If someone is showering and a toilet is flushed you can get a severe pressure drop on the cold and the possibiliy of scalding is very real

Larry, Sylvan: Thanks to both- After reading your reply's -- I do think we are on the same page for the most part. 1) I have to add plumbing to relo the WS, so PEX is the choice there. 2) I will keep the 1" feed to the inside to the manifold, maximzing volume 3) I will always have at least 3/4 mains running to any "room", 3/4 running to the HWH, and, either tap off those mains with 1/2" pex to a sink, toilet, etc, or go to the CW manifold where it makes sense to clean up plumbing. I think this way I will be maximizing volume to the individual endpoints.